Session time out error in weblogic log

Hello,

Recently i am facing a strange issue of session time out in my weblogic application.

My set up is as below:

Weblogic 11g on windows server

Databse 12g on Linux server

In between there is a network firewall with session time out setting of 120 min.

Problem: Once a connection is established between weblogic and databse via connection pool and remain idela for more than 120 min, we are getting session timeout for particlular datasource if we try to access application after 120 min.